Field
The embodiments described herein relate to a drilling liner assembly and method of use.
Description of the Related Art
A wellbore is formed by rotating and lowering a drill string, which has a drill bit connected at the lower end, into the earth. Drilling fluid is circulated into the wellbore while the wellbore is being drilled to remove the drilled earth and other wellbore debris. Drilling fluid is pumped down and out of the drill string into the wellbore, and flows back up to the surface through the annulus formed between the outer surface of the drill string and the inner surface of the wellbore, carrying out the drilled earth and other wellbore debris.
Sometimes, the wellbore is drilled into a low pressure zone, which causes the drilling fluid to flow into the low pressure zone and prevents removal of the drilled earth and other wellbore debris. The drilled earth and other wellbore debris that are not removed accumulate at the bottom of the wellbore and clog the annulus formed between the outer surface of the drill string and the inner surface of the wellbore, inhibiting further drilling of the wellbore. To isolate the low pressure zone, the drill string is removed and a liner string is lowered into the wellbore at a location above or adjacent to the low pressure zone.
Cement is pumped down and out of the liner string into the annulus formed between the outer surface of the liner string and the inner surface of the wellbore to cement the liner string in the wellbore and thereby isolate the low pressure zone. A drill string can then be lowered through the liner string to continue drilling the wellbore using another drilling fluid suitable for use in the low pressure zone. The separate liner string and cementing operations increase the time and costs of forming the wellbore.
Therefore, there is a continuous need for a new and improved wellbore drilling apparatus and methods.